Stock Fund

A stock fund or equity fund is a fund that invests in Equities more commonly known as stocks. Such funds are typically held either in stock or cash, as opposed to Bonds, notes, or other securities. This may be a mutual fund or exchange-traded fund. The objective of an equity fund is long-term growth through capital appreciation, although dividends and interest are also sources of revenue. Specific equity funds may focus on a certain sector of the market or may be geared toward a certain level of risk.
Stock funds can be distinguished by several properties. Funds may have a specific style, for example, value or growth. Funds may invest in solely the securities from one country, or from many countries. Funds may focus on some size of company, that is, small-cap, large-cap, et cetera. Funds which are managed by professionals are said to be actively managed where as Index funds try as best as possible to mirror specific market indices.
Index funds invest in securities to mirror a market index, such as the S&P 500. An index fund buys and sells securities in a manner that mirrors the composition of the selected index. The fund's performance tracks the underlying index's performance. Turnover of securities in an index fund's portfolio is minimal. As a result, an index fund generally has lower management costs than other types of funds. On a side note, these tend to have lower investment returns than other types, but offer the benefit of being (potentially) well diversified (if you happen to consider this a good thing).
These funds split investments between growth stocks, income stocks/bonds, and money market instruments or cash for stability. Fund advisers switch the percentage of holdings in each asset category according to the performance of that group. Example: A fund may have 60% invested in stocks, 20% in bonds, and 20% in cash or money market. If the stock market is expected to do well, that could switch to 80% stocks, and 10% each in both bond and cash investments. Conversely, if the stock market is expected to perform poorly, the fund would decrease its stock holdings.